Fluid ejection devices, such as printheads in inkjet printers, provide drop-on-demand ejection of fluid drops. Inkjet printers produce images by ejecting ink drops through a plurality of nozzles onto a print medium, such as a sheet of paper. The nozzles are typically arranged in one or more arrays, such that properly sequenced ejection of ink drops from the nozzles causes characters or other images to be printed on the print medium as the printhead and the print medium move relative to each other. In a specific example, a thermal inkjet printhead ejects drops from a nozzle by passing electrical current through a heating element to generate heat and vaporize a small portion of the fluid within an ink ejection chamber. In another example, a piezoelectric inkjet printhead uses a piezoelectric material actuator to generate pressure pulses in an ink ejection chamber that force ink drops out of a nozzle.
Prior to the ejection of ink drops from a nozzle, ink may travel from an ink reservoir to the ink ejection chamber through an ink feed slot that connects the chamber to the ink reservoir. Often, the ink feed slot is formed in a silicon substrate that is bonded to a body of the ink reservoir.